Influence of Design Parameters on the Cogging Torque of Permanent-Magnet Synchronous Generators

This paper presents an analysis of the influence that variations of the geometrical parameters of a Permanent Magnet Synchronous Generator (PMSG) have on the values of the cogging torque and induced electromotive force (emf). The following parameters were varied for this study: stator teeth width, stator slots isthmus width, length of permanent magnets pole arc and rotor yoke width. The effects of these parameters change on the PMSG behavior were quantitatively presented. The numerical analysis was performed by determining the magnetic field distribution inside the generator, using the finite element method (FEM); the cogging torque was determined together with the emf induced in the stator winding, at no-load and load operation. Numerical results validation was made by comparing measured with calculated emf values, for both no-load and restive load operating conditions.